places-menu: show the computer pretty name for the file system root

As Nautilus does, query hostnamed for the pretty hostname and watch
for changes.
If hostnamed is not available, we just show Computer, as before.

https://bugzilla.gnome.org/show_bug.cgi?id=693240

extensions/places-menu/extension.js

@@ -30,9 +30,24 @@ const PlaceMenuItem = new Lang.Class({
 	this.parent();
 	this._info = info;
 
-	this.addActor(new St.Icon({ gicon: info.icon,
-				    icon_size: PLACE_ICON_SIZE }));
-        this.addActor(new St.Label({ text: info.name }));
+        this._icon = new St.Icon({ gicon: info.icon,
+                                   icon_size: PLACE_ICON_SIZE });
+	this.addActor(this._icon);
+
+        this._label = new St.Label({ text: info.name });
+        this.addActor(this._label);
+
+        this._changedId = info.connect('changed',
+                                       Lang.bind(this, this._propertiesChanged));
+    },
+
+    destroy: function() {
+        if (this._changedId) {
+            this._info.disconnect(this._changedId);
+            this._changedId = 0;
+        }
+
+        this.parent();
     },
 
     activate: function(event) {
@@ -40,6 +55,11 @@ const PlaceMenuItem = new Lang.Class({
 
 	this.parent(event);
     },
+
+    _propertiesChanged: function(info) {
+        this._icon.gicon = info.icon;
+        this._label.text = info.name;
+    },
 });
 
 const SECTIONS = [

extensions/places-menu/placeDisplay.js

@@ -18,6 +18,11 @@ const Gettext = imports.gettext.domain('gnome-shell-extensions');
 const _ = Gettext.gettext;
 const N_ = function(x) { return x; }
 
+const Hostname1Iface = <interface name="org.freedesktop.hostname1">
+<property name="PrettyHostname" type="s" access="read" />
+</interface>;
+const Hostname1 = Gio.DBusProxy.makeProxyWrapper(Hostname1Iface);
+
 const PlaceInfo = new Lang.Class({
     Name: 'PlaceInfo',
 
@@ -28,6 +33,9 @@ const PlaceInfo = new Lang.Class({
         this.icon = icon ? new Gio.ThemedIcon({ name: icon }) : this.getIcon();
     },
 
+    destroy: function() {
+    },
+
     isRemovable: function() {
         return false;
     },
@@ -80,6 +88,47 @@ const PlaceInfo = new Lang.Class({
         }
     },
 });
+Signals.addSignalMethods(PlaceInfo.prototype);
+
+const RootInfo = new Lang.Class({
+    Name: 'RootInfo',
+    Extends: PlaceInfo,
+
+    _init: function() {
+        this.parent('devices', Gio.File.new_for_path('/'), _("Computer"));
+
+        this._proxy = new Hostname1(Gio.DBus.system,
+                                    'org.freedesktop.hostname1',
+                                    '/org/freedesktop/hostname1',
+                                    Lang.bind(this, function(obj, error) {
+                                        if (error)
+                                            return;
+
+                                        this._proxy.connect('g-properties-changed',
+                                                            Lang.bind(this, this._propertiesChanged));
+                                        this._propertiesChanged(obj);
+                                    }));
+    },
+
+    getIcon: function() {
+        return new Gio.ThemedIcon({ name: 'drive-harddisk-symbolic' });
+    },
+
+    _propertiesChanged: function(proxy) {
+        // GDBusProxy will emit a g-properties-changed when hostname1 goes down
+        // ignore it
+        if (proxy.g_name_owner) {
+            this.name = proxy.PrettyHostname || _("Computer");
+            this.emit('changed');
+        }
+    },
+
+    destroy: function() {
+        this._proxy.run_dispose();
+        this.parent();
+    }
+});
+
 
 const PlaceDeviceInfo = new Lang.Class({
     Name: 'PlaceDeviceInfo',
@@ -218,14 +267,13 @@ const PlacesManager = new Lang.Class({
         let networkMounts = [];
         let networkVolumes = [];
 
+        this._places.devices.forEach(function (p) { p.destroy(); });
         this._places.devices = [];
+        this._places.network.forEach(function (p) { p.destroy(); });
         this._places.network = [];
 
         /* Add standard places */
-        this._places.devices.push(new PlaceInfo('devices',
-                                                Gio.File.new_for_path('/'),
-                                                _("Computer"),
-                                                'drive-harddisk-symbolic'));
+        this._places.devices.push(new RootInfo());
         this._places.network.push(new PlaceInfo('network',
                                                 Gio.File.new_for_uri('network:///'),
                                                 _("Browse Network"),